import UIKit

public enum RDEPUBReaderDisplayMode: String, Codable, Equatable {
    case pageCurl
    case horizontalScroll
    case verticalScroll
    case horizontalCoverScroll

    init(displayType: RDReaderView.DisplayType) {
        switch displayType {
        case .pageCurl:
            self = .pageCurl
        case .horizontalScroll:
            self = .horizontalScroll
        case .verticalScroll:
            self = .verticalScroll
        }
    }

    var displayType: RDReaderView.DisplayType {
        switch self {
        case .pageCurl:
            return .pageCurl
        case .horizontalScroll, .horizontalCoverScroll:
            return .horizontalScroll
        case .verticalScroll:
            return .verticalScroll
        }
    }
}

public enum RDEPUBReaderThemePreset: String, Codable, CaseIterable, Equatable {
    case light
    case yellow
    case green
    case pink
    case blue
    case dark

    public var theme: RDEPUBReaderTheme {
        switch self {
        case .light:
            return .light
        case .yellow:
            return .yellow
        case .green:
            return .green
        case .pink:
            return .pink
        case .blue:
            return .blue
        case .dark:
            return .dark
        }
    }

    public init?(theme: RDEPUBReaderTheme) {
        switch theme {
        case .light:
            self = .light
        case .yellow:
            self = .yellow
        case .green:
            self = .green
        case .pink:
            self = .pink
        case .blue:
            self = .blue
        case .dark:
            self = .dark
        default:
            return nil
        }
    }
}

public struct RDEPUBReaderSettings: Codable, Equatable {
    public var brightness: CGFloat?
    public var fontSize: CGFloat?
    public var lineHeightMultiple: CGFloat?
    public var displayMode: RDEPUBReaderDisplayMode?
    public var themePreset: RDEPUBReaderThemePreset?

    public init(
        brightness: CGFloat? = nil,
        fontSize: CGFloat? = nil,
        lineHeightMultiple: CGFloat? = nil,
        displayMode: RDEPUBReaderDisplayMode? = nil,
        themePreset: RDEPUBReaderThemePreset? = nil
    ) {
        self.brightness = brightness
        self.fontSize = fontSize
        self.lineHeightMultiple = lineHeightMultiple
        self.displayMode = displayMode
        self.themePreset = themePreset
    }

    public func applying(to configuration: RDEPUBReaderConfiguration) -> RDEPUBReaderConfiguration {
        var resolvedConfiguration = configuration

        if let fontSize {
            resolvedConfiguration.fontSize = fontSize
        }
        if let lineHeightMultiple {
            resolvedConfiguration.lineHeightMultiple = lineHeightMultiple
        }
        if let displayMode {
            resolvedConfiguration.displayType = displayMode.displayType
        }
        if let themePreset {
            resolvedConfiguration.theme = themePreset.theme
        }

        return resolvedConfiguration
    }

    public static func capture(
        configuration: RDEPUBReaderConfiguration,
        brightness: CGFloat
    ) -> RDEPUBReaderSettings {
        RDEPUBReaderSettings(
            brightness: max(0, min(1, brightness)),
            fontSize: configuration.fontSize,
            lineHeightMultiple: configuration.lineHeightMultiple,
            displayMode: RDEPUBReaderDisplayMode(displayType: configuration.displayType),
            themePreset: RDEPUBReaderThemePreset(theme: configuration.theme)
        )
    }
}